Efficient constitution of a vector-hydrophone for boundryless direction-finding [boundryless reads boundary less]

An underwater acoustic vector-hydrophone is composed of two or three spatially collocated but orthogonally oriented velocity-hydrophones, plus an optional collocated pressure-hydrophone. An efficient vector-hydrophone configuration is herein identified for finite-variance direction-finding by identifying the necessary and sufficient vector-hydrophone composition configuration non-singularity in the Fisher Information Matrix. Recommended for boundary less direction-finding are three collocated velocity hydrophones, one along the x-axis, y-axis and z-axis.